Method for providing enhanced directory assistance upon command using out-of-band signaling

ABSTRACT

A user calls a directory assistance service provider to search for a desired telephone number and be connected to a party at the desired number. In one such connection, the user is afforded enhanced directory assistance upon a user command in the form of an out-of-band signaling message, e.g., SS7 signaling message. For example, the user may be afforded further operator assistance by pressing on the user telephone a predetermined key (e.g., “*” key), which is detectable by the directory assistance service provider as an SS7 signaling message.

RELATED APPLICATION DATA

[0001] The present application is a continuation in part of copendingU.S. patent application Ser. No. 09/135,155, filed Aug. 17, 1998, whichis a continuation of U.S. patent application Ser. No. 08/552,222, filedNov. 2, 1995, issued Aug. 18, 1998 as U.S. Pat. No. 5,797,092, which isa continuation-in-part of U.S. patent application Ser. No. 08/498,900,filed Jul. 6, 1995, now abandoned, which is a continuation-in-part ofU.S. patent application Ser. No. 08/234,644, filed Apr. 28, 1994, nowabandoned.

FIELD OF THE INVENTION

[0002] The present invention relates to systems for providing directoryassistance services, and more particularly relates to the provision ofdirectory assistance services in a network using out-of-band signaling.

BACKGROUND AND SUMMARY OF THE INVENTION

[0003] Telephone directory assistance services have been available forthe past century. While improvements have been made over the decades,such systems are still poorly suited for use by subscribers of wirelesstelephone services.

[0004] In prior art directory assistance services, a customer dials anoperator and identifies the name and address of a party whose telephonenumber is desired. The operator then locates the number using printeddirectories or a computer database, and provides the number to thecustomer. (The provision of the number is sometimes done by the liveoperator, but more typically is done with a computerized voice responseunit that provides connection to the operator is terminated.

[0005] While satisfactory for most customers, this arrangement isill-suited for many wireless telephone customers. For one, suchcustomers are usually away from their general work environments (e.g. ina vehicle), and thus may not have ready access to a pencil and paper inorder to make a note of the desired number. (Even if such materials areavailable, the customer may not find it convenient to interrupt otheractivities, e.g. driving, in order to make a note.) In addition, theprocess of initiating a second call—to the desired party—entails furthermanual operations (e.g. hanging up, waiting for another dial tone, anddialing) which may be a hindrance to the customer's other activities.

[0006] The present assignee, in the prior art, has redressed certain ofthese difficulties by providing a directory assistance service thateliminates the need to make a note of the desired number, or undertake aredialing exercise. Instead, after determining the telephone numberdesired by the customer, rather than voicing it to the customer, thedirectory assistance operator goes ahead and initiates a call to thedesired party, and connects the new outgoing call to the originalcustomer. (The operator may stay on the line as a conferenced party soas to provide further assistance, or may withdraw from the connection,depending on the particular implementation.) This arrangement obviatesthe need for the customer to make a note of the voiced number, or toundertake a redialing exercise. However, if the initiated call is notcompleted (e.g. a “busy” tone is received), or if the customer desiresfurther directory assistance, then the customer must again call thedirectory assistance operator for help.

[0007] The problems associated with providing directory assistanceservices to wireless customers are not limited to hardships on thecustomers; the directory assistance service and the wireless carrieralso confront unique issues. In the assignee's prior art system, forexample, the wireless carrier (which is typically responsible forbilling of the customer) knows only that the customer has dialed thedirectory assistance operator, but does not know the number to which thecustomer is ultimately connected by the operator. Billing is therebycomplicated. In the prior art system, the toll charges (assuming tollcalls are permitted; often they are not) for the connection between thecustomer and the desired number are simply absorbed by the directoryassistance service, and recouped by billing the wireless carrier asufficiently large flat rate charge for each directory assistance callso as to cover these costs. The wireless carrier then bills thesubscriber a fixed amount for each directory assistance inquiry,regardless of the toll charges of any further connection established forthe customer by the directory assistance operator. This arrangement,however, has a number of disadvantages. In addition to increased cost,it also fails to provide the wireless carrier useful information aboutits customers' calling patterns, which may affect decisions relating tosystem expansion, etc.

[0008] The directory assistance method disclosed herein overcomes theseproblems of the prior art. For example, in one embodiment of the presentinvention, a customer who wishes directory assistance services isconnected in the conventional manner to an operator who determines thedestination telephone number desired by the customer. As in the priorart, the operator then initiates a call connecting the customer to thedestination telephone number. However, rather than dropping all furtherinvolvement with the call, this embodiment is capable of detecting acommand to reconnect to an operator issued by the customer, such as thatobtained by pressing the “*” button or some other button. If such asignal is detected, the customer is transferred to a directoryassistance operator, who can then provide whatever further assistance isneeded (e.g. redialing a busy number, or providing further directoryassistance). By this arrangement, the press of a single button by thecustomer summons further directory assistance, rather than the redialingprocedure required by the prior art.

[0009] To achieve this type of customer-driven functionality, thepresent invention is responsive to commands issued by the customer, forexample by pressing a key on the telephone. The commands can be detectedat the directory assistance switch by a DTMF receiver, or alternatively,may appear at the directory assistance service center as out-of-bandsignals on an associated signaling channel, independent of the actualvoice channel.

[0010] Out-of-band signaling, as is well-known in the art, involvesseparating the voice and signaling components of a call into twoseparate components. The signaling information is transmitted on asignaling data link, and the voice and data traffic components aretransmitted over a voice trunk. A signaling data link is atwo-directional transmission path (a typical carrier channel) forsignaling, comprising transmit and receive data channels operatingtogether in opposite directions at the same data rate. The signalinginformation typically contains connection-oriented signaling such asaddress information for call setup, supervision/call control signaling,tear down, information needed for distributed application processing andnetwork management information.

[0011] Signaling data is typically transmitted in packets betweennetwork nodes in what is known as a Common Channel Signaling (“CCS”)system. One example of a standardized, general-purpose protocol for aCCS system is Signaling System 7, or “SS7.” SS7 is an open-architectureprotocol that handles current communication requirements andaccommodates future expansion of new applications. It is optimized foroperation in a digital telecommunications network in conjunction withstored program control switches. SS7 meets present and futurerequirements for information transfer (circuit and non-circuit related)for interprocessor transactions within telecommunication networks forcall control, network database access, and management and maintenancesignaling. Furthermore, SS7 provides a reliable means of informationtransfer, correctly sequenced, without loss or duplication.

[0012] The SS7 standard for telecommunications is global, defined by theInternational Telecommunication Union (ITU) TelecommunicationStandardization Sector (ITU-T). The standard defines the procedures andprotocol by which network elements in the public switched telephonenetwork (PSTN) exchange information over a digital signaling network.The ITU definition of SS7 is designed to allow for national variants,such as the American National Standard Institute (ANSI) and BellCommunications Research (Bellcore) standards used in North America, andthe European Telecommunications Standards Institute (ETSI) standard usedin Europe. The naming conventions have been defined as follows: CCITTSS#7 indicates International Signaling system 7, and SS7 indicates theU.S. version of Signaling System 7. SS7 has been appropriately modifiedfor use with and between U.S. networks. SS7 is intended to be generallycompatible with CCITT SS#7.

[0013] SS7 transport has become the primary mode for signaling andinformation transfer in today's wireless and wireline networks.Information elements like calling party number, routing informationrelated to 800 numbers, and current location information for roamingwireless subscriber are all carried over SS7 signaling networks. SS7makes features such as call waiting, three-way calling and caller IDpossible. The benefits of the SS7 protocol include more efficient callprocessing, AIN products and services (Advanced Intelligent Network:service-independent capabilities used in SS7 to support advancedfeatures), better reliability, faster call processing, faster call setup and tear down, and more accurate signaling detection. With SS7,regular voice lines are not tied up until the call is actuallyestablished or the destination number has been identified as available(through the signaling data link)—about 40% of all calls made are notcompleted because of either a busy signal or no answer.

[0014] SS7 call processing provides great flexibility in receivingand/or responding to customer-issued commands. For example, in oneembodiment of the present invention a customer can issue a command forconferencing by pushing a key on the customer's phone (e.g. the “*”key), which is detected at the directory assistance service center as anSS7 message. Then, either a directory assistance operator or anautomated system determines the telephone number of an additional partythe customer wishes to conference in, and a telephonic connectionbetween the additional party and the existing connection is initiatedusing SS7 call processing. The operator or automated system can continueto add additional parties or delete parties as desired by the customerusing SS7 call processing, or the customer can reinitiate the procedureat a later time to further change the participating parties.

[0015] Alternatively, the command for conferencing by the customer couldbe detected by a DTMF tone receiver on the voice channel, while callinitiation and processing occurs through SS7 signaling.

[0016] In another embodiment of the present invention, the directoryassistance center, in attempting to initiate a telephonic connectionbetween the customer and the customer's desired customer, takes certainactions upon detection of a SS7 signaling message indicting connectionproblems (such as ring-no-answer or call could not be completed). Theactions include either directly reconnecting the customer, or offeringthe customer a variety of automated menu options, including returning toan operator.

[0017] In yet another embodiment, upon receiving a call from a customerat the directory assistance service, a preferred service associated withthat customer is determined from a customer attribute database, or inthe event the customer does not have an associated preferred service, adefault service chosen. Upon detection of a SS7 signaling message orDTMF tone indicating the customer has issued a command for the preferredservice, the directory assistance service center actuates the preferredservice using SS7 call processing, whether it be reconnecting to anoperator, conferencing in other parties, or any other of a variety ofenhanced directory assistance features.

[0018] The directory assistance system disclosed herein furtheraddresses the billing difficulties associated with completion ofcustomer calls by directory assistance operators. In one embodiment ofthe invention, the directory assistance service logs, in a billingdatabase, information identifying the customer (i.e. the customeridentification number accompanying the call from the wireless provider),the destination number to which the customer is connected, and the date,time and duration of the customer/destination number connection. Thislog of information is periodically provided to the wireless carrier,allowing it to bill the customer for the call connected by the directoryassistance operator and recoup the associated expense. This permits theflat rate charged by the directory assistance provider to be reducedcorrespondingly, and provides the wireless service with more detailedinformation about its customers' usage requirements.

[0019] The foregoing and additional features and advantages of thepresent invention will be more readily apparent from the followingdetailed description, which proceeds with reference to the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIGS. 1a-b are block diagrams depicting a prior art SS7 network.

[0021]FIG. 1c is a block diagram depicting call setup and initializationin a prior art SS7 network.

[0022]FIG. 2 depicts the components of a directory assistance centeraccording to the invention.

[0023]FIG. 3 provides a detailed view of a switching matrix platformused in one embodiment of the invention;

[0024]FIG. 4 provides a detailed view of a voice server used in oneembodiment of the invention.

[0025]FIG. 5 is a flow chart depicting the process of sending a datapacket to the switching matrix host in accordance with one embodiment ofthe present invention.

[0026]FIG. 6 is a flow chart depicting the process of maintaining thedirectory assistance operator as a conferenced party to the initiatedtelephonic connection in accordance with one embodiment of the presentinvention.

[0027]FIG. 7 is a flow chart depicting the process of allocating a DTMFreceiver in the telephone switch to a customer call for the entireduration of the call in accordance with one embodiment of the presentinvention.

[0028]FIG. 8 is a flow chart depicting the process of disabling tonetriggered return transfer in accordance with one embodiment of thepresent invention.

DETAILED DESCRIPTION

[0029] The present invention contemplates a directory assistance centeroperating in conjunction with a SS7 network. Turning to FIG. 1a, a SS7network by functional component is shown. A SS7 network is composed of aplurality of service switch points (SSP), signal transfer points (STP)and signal control points (SCP). An SSP is generally atelecommunications switch, access tandem or end office which caninteract with the SS7 network for data base services. For purposes ofthe present invention, the SS7 network node of the directory assistancecenter disclosed herein operates as an SSP.

[0030] SSPs send signaling messages to other SSPs to setup, manage, andrelease voice circuits required to complete a call. An SSP may also senda query message to an SCP, which is a centralized database typicallycontaining a routing table, to determine how to route a call. Networktraffic between SSPs is typically routed via a STP (a packet switch orrouter). An STP routes each incoming message to an outgoing signalinglink, such as an SSP or another STP, based on routing informationcontained in the SS7 message. STPs eliminate the need for direct linksbetween signaling points.

[0031] As shown in FIG. 1b, SCPs and STPs are usually deployed in matedpair configurations, in separate physical locations to ensurenetwork-wide service in the event of an isolated failure. Also, SS7signaling data links (which connect the SSPs, STPs and SCPs) typicallycome in pairs for redundancy. Traffic is load shared between the linkpairs. The link pairs are installed as physically distinct pathsthroughout their complete routes (i.e. they are diverse), generallyplaced on different interexchange carriers. This configuration ensuresthat a problem on one facility will not interfere with the normaltraffic flow. The redundancy and diversity incorporated into a SS7network reflects the SS7 signaling network's importance in callprocessing.

[0032] Physically, both SS7 signaling data and voice traffic arecommonly transmitted on a DS1 or T1/E1/J1 carrier. While a T1/E1/J1carrier has 24 or 30 individual channels of 64 kb/s lines, a SS7 circuitis designed to operate at 56 kb/s, utilizing the other 8 kb/s forclocking and error checking.

[0033] With reference to FIG. 2, a directory assistance center 10according to one embodiment of the present invention includes aswitching matrix platform 14, also referred to as a private branchexchange (PBX) or switch, connected to one or more external T1/E1/J1voice connections 12 and one or more corresponding T1/E1/J1 dataconnections 13 from customer networks. While pictured as physicallyseparate channels, data connections 13 may comprise a physical channelwithin voice connections 12, such as a DSO channel within a TI line.Switching matrix platform 14 is also connected via T1 communicationlinks to a voice response unit (VRU) 30, and to a channel bank 16 forcoupling to a plurality of operator telephones 18. Each operator isfurther equipped with a terminal 20 that includes a video display unitand a QWERTY keyboard with associated dialing pad. The operatorterminals are coupled over a data network 24 to a database server 26,allowing an operator to access the data in database server 26 throughthe operator terminal 20. In one embodiment, data network 24 is a LocalArea Network (LAN).

[0034] In addition to the operator terminals, data network 24 furtherconnects to a voice response unit (VRU) 30 and a switching matrix hostcomputer 28 (also referred to as a PBX host), which in turn is connectedto switching matrix platform 14 by switch data link 22. In oneembodiment, VRU 30, database server 26, and switching matrix host 28have redundant systems (as shown), which can operate as either back-upsystems in the event of primary system failure, or provide load-sharingin a master-slave relationship with the primary system.

[0035] Voice connections 12, also referred to as voice links, provideconnection between the directory assistance center's switching matrixplatform 14 and carrier switching center 34, through which incomingdirectory assistance calls are received. Voice connections 12 furtherprovide connection to the network over which outgoing calls are placed(which network may be different than that used for incoming traffic).Similarly, data connections 13, also referred to as data links, providea signaling connection between the directory assistance center's nodeand the carrier's SS7 network node 36. In the event an outgoing call isplaced on a different network than the calling customer's carrier'snetwork, voice connections 12 and data connections 13 will also provideconnection to the outgoing network's switch and node, respectively.

[0036] In one embodiment of the present invention, the directoryassistance node in is contained within switching matrix platform 14, butone of skill in the art will appreciate that the directory assistancenode could also be a physically distinct component.

[0037] In terms of SS7 network functional components (see FIG. 1b), thedirectory assistance node operates as a SSP. The carrier's SS7 networknode 36 may either be a SSP if the carrier is directly linked to thedirectory assistance center, or it may be a STP whereby calls from thecarrier's SSP are routed through the carrier's SS7 network node/STP (ormultiple STPs) to the directory assistance center. Alternatively, SS7signaling for the carrier may be transmitted through an independent SS7network provider, in which instance data connections 13 would connect tothe STP of a SS7 network provider independent from either the incomingor outgoing carrier's network. Neither an independent SS7 networkprovider nor an independent outgoing network are shown in FIG. 2.

[0038] Operation of switching matrix platform 14 is governed bycomputer-readable instructions stored and executed on switch matrix hostcomputer 28. In one embodiment of the invention, switching matrixplatform 14 is an Excel LNX 2000 and switch data link 22 is a 38.4 kbserial link; in another embodiment, switch data link 22 is an Ethernetlink.

[0039] Switching matrix platform 14 is described in further detail withreference to FIG. 3. Switching matrix platform 14 includes expandablecentral processing unit (“EXCPU”) 304 and/or matrix central processingunit (“MXCPU”) 304. EXCPU/MXCPU 304 serves as an interface betweenswitching matrix platform 14 and switching matrix host computer 28 (viaswitch data link 22).

[0040] Switching matrix platform 14 also includes SS7 processingcomponents, namely SS7 I/O cards 340, each of which can concurrentlysupport up to 16 links. In one embodiment, the switching matrix platformhas two SS7 I/O cards, although in an EXS 2000 switching matrix platformup to eight SS7 I/O cards (128 concurrent links) can be supported. Afurther redundant pair of SS7 I/O cards (not shown) provides back-up.SS7 I/O cards 340 work in conjunction with SS7 computer instructionsstored on switching matrix host 28 for SS7 call processing such ascustomer-issued commands for service, call setup, control signaling andtear down, etc. With respect to the SS7 network described at FIGS. 1aand 1 b and discussed above, the switching matrix platform acts as aservice switching point (SSP), also referred to as the directoryassistance node.

[0041] EXCPU/MXCPU 304, SS7 I/O cards 340 and other components ofswitching matrix platform 14 communicate through shared communicationpath 302, commonly called a “midplane.” In the currently-describedembodiment, midplane 302 utilizes a time division multiplexing (“TDM”)method of sharing a common pathway. Thus, a plurality of data and/orvoice streams can be interlaced onto the single path, separated by time.

[0042] Another board-level component of switching matrix platform 14 ismulti-frequency digital signal processor (“MFDSP”) unit 310, whichincludes four single in-line memory module (“SIMM”) packagings. EachSIMM packaging is comprised of four DSP arrays. Each DSP array iscomposed of multiple, illustratively sixteen, programmable DSPs. TheDSPs can be programmed or reprogrammed to function as, among otherthings, call progress analyzers (“CPA”), call progress generators(“CPG”), multi-frequency (“MF”) receivers or transmitters, dual-tonemulti-frequency (“DTMF”) receivers or transmitters, or conference units,depending upon the demand placed on directory assistance center 10 andswitching matrix platform 14 for each corresponding function.

[0043] CPAs (represented by the numeral 318 in FIG. 3) are sensitive to,and capable of identifying, telephone connection status conditions andsignals including ring tone, busy, all-circuits-busy, tri-tone, reorder,PBX intercept, SIT intercept, vacant code, reorder LEC, no circuit LEC,reorder carrier, no circuit carrier, continuous on tone, and silence. Inan exemplary embodiment of the invention, one CPA will monitor only oneoutbound channel at a time. In other embodiments of the invention, oneCPA may be applied to more than one outbound channel. However, to ensurethat connection status conditions are properly detected, the number ofoutbound channels monitored by one CPA should be kept to a minimum(i.e., no more than four). In still other embodiments of the invention,two or more DSPs may be applied to a single outbound channel.

[0044] CPGs (represented by the numeral 312 in FIG. 3) generate tones tocustomers connected to directory assistance center 10, such as theringback tone customers hear when they are routed to an operator.

[0045] DTMF receivers (represented by the numeral 314 in FIG. 3) listenfor DTMF tones generated by a customer's telephone, such as when acustomer presses a telephone button. DTMF receivers are capable ofdetecting and identifying which button was pressed (i.e., the numbers0-9 or the characters ‘*’ or ‘#’) and passing that information toswitching matrix host 28 for appropriate action. DTMF receivers areassigned to monitor inbound channels for a configurable period of time,illustratively, from the time of a caller's initial connection toswitching matrix platform 14 to the time the caller hangs up, includingthe duration of all outbound calls made on the caller's behalf. Onceapplied to an inbound channel, a DTMF receiver will allow switchingmatrix platform 14 to detect whenever the caller presses a telephonebutton, perhaps in order to activate a return transfer as describedfurther herein, or another feature of directory assistance center 10.

[0046] Conference units (represented by the numeral 316 in FIG. 3)enable switching matrix platform 14 to connect two or more voice pathsin a balanced manner, thereby providing the necessary voice connectionsbetween calling parties, called parties, and directory assistanceproviders.

[0047] In the presently-described embodiment, each DSP array providesmultiple instances of the function for which it is programmed, the exactnumber depending upon the specific function. For example, each DSP arrayprogrammed to provide CPA, CPG, or DTMF receiver functions providessixteen instances of the chosen function. In other words, a DSP arrayprogrammed to provide call progress analyzer functions will containsixteen separately and independently functional and controllable CPAs. ADSP array programmed to provide conference unit functions, however,provides only four instances of such function. The programmable DSPs onMFDSP unit 310 are managed by switching matrix host 28, via EXCPU/MXCPU304, which keeps track of which DSPs are available and which areallocated.

[0048] An additional board-level component of switching matrix platform14 is T1/E1/J1 interface unit 330. Switching matrix platform 14 containsone or more T1/E1/J1 interface units; each unit provides connections tomultiple T1/E1/J1 (1.544 mb/sec) spans, each of which is comprised of 24or 30 channels, thus providing at least 192 64 kb voice/data and/or SS7signaling channels per T1/E1/J1 interface unit. The T1/E1/J1 interfaceunits connect to T1/E1/J1 voice connections 12 and T1/E1/J1 dataconnections 13. In an alternative embodiment (not shown), T1/E1/J1 dataconnections 13 (the out-of-band signaling channel) may connect directlyto SS7 I/O cards 340.

[0049] In FIG. 3, T1/E1/J1 interface 330 dedicates twelve channels oneach of six of the eight spans to incoming calls and the other twelve tooutgoing calls. The seventh T1/E1/J1 span serves as the T1 link betweenVRU 30 and switching matrix platform 14, and the eighth functions as aT1 link to channel bank 16 and operator telephone 18. The link betweenswitching matrix platform 14 and VRU 30 is used to connect callingcustomers to a voice server, while the link between switching matrixplatform 14 and operator telephone 18 is used to connect callingcustomers to a live operator.

[0050] A similar switching matrix platform to the one described hereinis described in copending application Ser. No. 08/816,921, also assignedto the present assignee, the contents of which are herein incorporatedby reference. It will be recognized by one skilled in the art that avariety of types of, or even multiple instances of, switching matrixplatform 14 may be incorporated into a telephone network or directoryassistance center 10 without exceeding the scope of this invention.

[0051] Switching matrix platform 14's operation is governed byinstructions stored in switching matrix host computer 28. Switchingmatrix host computer 28 stores and executes computer-readableinstructions for the purposes of, among others, configuring andoperating switching matrix platform 14 and directing the transfer ofcalls through the switching matrix platform. The instructions implementthe processes hereafter described, as well as provide full SS7functionality. In alternative embodiments, the instructions may supportany other appropriate type of out-of-band signaling protocol. Theswitching matrix host also directs the playback of recorded messages tocallers connected to the directory assistance center. Pre-recordedgreeting and closing messages played for callers are recorded in thevoice of the operator to whom the caller will be, or was, connected.Switching matrix host 28 directs the playback of the appropriate messageby identifying the voice connection 12 the caller is connected to andspecifying the message to be played.

[0052] Further, switching matrix host 28 maintains call data for eachdirectory assistance call connected to directory assistance system 10.The call data stored on the host computer consists of the most recentassistance request received from each caller, and includes one or moreof: the calling telephone number, the date and time of the caller'sconnection to directory assistance center 10, the T1/E1/J1 span andchannel the caller is connected to, the caller's desired destinationtelephone number, the status of the caller's previous directoryassistance request, which operator assisted the caller, etc. Additionalcall data is stored on database server 26, as described below. The calldata stored on switching matrix host 28 and database server 26 areprovided to directory assistance providers when a caller makes multipledirectory assistance requests in one call to directory assistance center10. By considering the collected call data, such as the information thatwas provided to a caller in a previous request, a directory assistanceprovider can tailor subsequent assistance to be more effective.

[0053] Switching matrix host 28 also directs the transfer of informationbetween itself and database server 26 (via data network 24), as well asbetween switching matrix platform 14 and database server 26, operatortelephone 18, and channel bank 16. Although the switching matrix host 28and database server 26 are depicted as distinct devices in FIG. 2, in analternative embodiment they are both found in the same physical device.Furthermore, although one primary database server 26 is pictured, one ofskill in the art will appreciate that multiple database servers may bebeneficial and hence utilized instead.

[0054] Incoming calls received by switching matrix platform 14 areconnected to an available operator via a T1 span 32 that is connectedthrough channel bank 16 to an operator's telephone headset. If nooperator is available when a call is received, the call is queued untilan operator becomes available. In one embodiment, the queuing and calldistribution is Automatic Call Distribution (ACD), but one of skill inthe art will also appreciate that another method of call distributionbased on a different priority scheme could be utilized as well.

[0055] Database server 26 provides operators with the means to searchfor a customer's desired party, and determine the appropriate telephonenumber. In one embodiment, the database provides the capability tosearch not just by name and address, but also by type of goods/servicesand/or geographical region, or by any other attribute in the customerrecord, including phone number. (E.g. the preferred database can answerqueries soliciting the names/numbers of shops carrying model rocketrysupplies in southeast Portland, Oreg., or of Chinese restaurants on agiven street.) Data indexed in this fashion is usually not commerciallyavailable, so the present assignee starts with a commercially availabledatabase file (e.g. the Directory Assistance Database Source availablefrom U.S. West), and enriches it by adding further data manually.

[0056] Desirably, the results of the database search presented onoperator's terminal 20 are not alphabetized prior to display, but ratherare presented in the order located by the database search engine. (Ifdesired, a deliberate randomization of order could be effected beforedisplay). Businesses at the beginning of the alphabet are thereby notunduly favored by customers using the directory assistance service.

[0057] The database software itself is conventional. The presentlypreferred best mode is to use a database such as dB-One, a proprietarysystem available from the present assignee.

[0058] In another embodiment, database server 26 further includes apreferred service associated with each customer, or, in the absence of aspecified preferred service, a default service. Examples of preferredservices would include such features as returning to an operator,conferencing, re-attempting to establish a telephonic connection,creating a voice mail to be delivered at a later time, etc. Thedirectory assistance center utilizes the preferred service associatedwith each customer by performing the appropriate service upon issuanceof a command by the customer to do so. The customer is thus able toobtain, at the issuance of single command, the service he or she valuesmost or uses most often, unique to that customer.

[0059] Voice response unit (VRU) 30 is incorporated into the system toplay the constantly repeated parts of an operator's speech, namely thevarious greetings and signoffs (or closings), and the caller's desiredtelephone number where requested. Not only does this system provide avoice-saving and monotony-relief function for the operators, it performsa “branding” function (i.e. the pre-recorded messages incorporate thename of the telephone company through which the customer was routed tothe directory assistance service), and it also reduces the amount oftime an operator is actually connected to a customer. The VRU may alsocontain a voice recognition system for receiving verbal input from aparty connected to the VRU.

[0060] In an illustrative embodiment in FIG. 4, VRU 30 is connected viathe data network 24 to database server 26, switching matrix host 28 (towhich it acts as a slave processor) and switching matrix platform 14 viaone or more T1 spans. Each VRU, when more than one is employed indirectory assistance center 10, connect to switching matrix platform 14via a separate voice server link. VRU 30 consists of a general purposecomputer plus one or more voice cards (a first voice card 402 isdepicted in FIG. 4), which serve as the interface between VRU 30 and theT1 span to switching matrix platform 14. Voice card 402 monitors andcontrols communications over the T1 span; its capabilities includetelephone tone detection and generation, voice recording and playback,and call progress analysis. Therefore, very similar to switching matrixplatform 14, VRU 30 is capable of detecting connection statusconditions, detecting customer keypresses, and generating tones.Although FIG. 2 depicts VRU 30 distinct from database server 26, inalternative embodiments they are coterminous.

[0061] VRU 30 also includes typical computer components such as centralprocessing unit 404, data storage unit 406, and bus 410 for transferringvoice and data signals. VRU 30 also contains a voice recognition card412 for receiving verbal input from a party connected to the voiceserver.

[0062] At appropriate stages in a call progression, switching matrixhost 28 initiates a voice path between the VRU and the switching matrixplatform such that the caller, or the caller and the operator, are ableto hear whatever pre-recorded speech is played on that circuit by theVRU. Switching matrix host 28 then instructs the VRU, via data network24, what type of message to play, passing data parameters that enablethe VRU to locate the message appropriate to the call state, theservice-providing telephone company, and the operator. The recordingdensity used is high enough to provide a good enough quality of messageplayback that most users of the system should be unaware they arelistening to a recording.

[0063] Method of Operation

[0064] Customers of a particular telephone company simply dial theaccess digits established for directory assistance by that company.Examples of typical access digits are “411,” “*555,” “555-1212” and“NPA-555-1212.”

[0065] The participating telephone company's own switching system willthen reroute the call to directory assistance service center 10 (via aT1/E1/J1 channel), where it appears as an incoming call. In a SS7network, the telephone company or wireless carrier transmits call set-upinformation associated with the call from the telephone company'snetwork node to the directory assistance center node (also via aT1/E1/J1 channel). For purposes of illustration, a SS7 call initiationprocedure will be described, which is utilized not only in routing acustomer's call to the directory assistance center, but also by thedirectory assistance center in connecting the calling customer to thedesired number.

[0066] As shown in FIG. 1c, the phone company (as the originating SSMhere) first transmits an Initial Address Message (IAM) to reserve anidle voice trunk circuit from the originating switch to the destinationswitch (in the present instance, the destination switch would beswitching matrix platform 14). The destination switch examines thedialed number, determines that it serves the called party and that theline is available for ringing. The destination switch then transmits anAddress Complete Message (ACM) to the originating switch to indicatethat the remote end of the voice trunk has been reserved. Thedestination switch rings the called party line and sends a ringing toneover the voice trunk to the originating switch. When the originatingswitch receives the ACM, it connects the calling party's line to thevoice trunk to complete the voice circuit from the calling party to thecalled party. The calling party hears the ringing tone on the voicetrunk. When the called party picks up the phone, the destination switchterminates the ringing tone and transmits an Answer Message (ANM) to theoriginating switch. The originating switch then verifies that thecalling party's line is connected to the reserved voice trunk and, ifso, initiates billing.

[0067] During the course of the call, if the calling party hangs upfirst, the originating switch sends a Release Message (REL) to releasethe voice trunk circuit between the switches. Upon receiving the REL,the destination switch disconnects the voice trunk from the calledparty's line, sets the voice trunk state to idle, and transmits aRelease Complete Message (RLC) to the originating switch to acknowledgethe remote end of the voice trunk circuit. When the originating switchreceives the RLC, it terminates the billing cycle and sets the voicetrunk state to idle in preparation for the next call. On the other hand,if the called party hangs up first, or if the line is busy, thedestination switch sends a REL to the originating switch indicating therelease cause, such as a normal release or busy condition. When theoriginating switch generates the RLC, it terminates the billing cycleand sets the voice trunk to idle.

[0068] Once the SS7 call initiation procedure is complete, and acustomer's call has been “answered” by directory assistance center 10,Automatic Call Distribution (ACD) logic is used to queue (if necessary)and distribute the call to an operator in the order in which it wasreceived, and such that the call traffic is distributed evenly among theoperators. In other embodiments, other distribution logic schemes areutilized, such as Skills-Based Routing or a priority scheme forpreferred customers. The queue is maintained by switching matrix host28.

[0069] When a call is connected to an operator, switching matrix host 28directs VRU 30 (also conferenced into the call) to play a greetingmessage, using a message pre-recorded by the connected operator. Boththe operator and the calling customer hear the message, whichincorporates the name of the service or company to which the customer isa subscriber (in other words, the call is “branded”). The message endswith a prompt, thus cuing the customer to volunteer what informationthey are seeking.

[0070] When the automated greeting is complete, the VRU is disconnected,and the operator and the customer are left connected by a 2-way speechpath. From this point, the caller is interacting with a live operator.

[0071] In the event that the VRU is non-functional (for whateverreason), the incoming call is connected to the operator and a shorttrill, or “zip” tone is played to indicate that a caller is on the line.(Note that, in one embodiment, once operators are logged in to thesystem, they wear headsets and have their telephones 18 permanentlyoff-hook. Their telephones do not ring when a call is presented.) Theoperator then speaks a greeting and prompt in real time, instead of theVRU playing a message.

[0072] If the caller requests information concerning, for example, localtheater performances, the operator speaks a response based on hard copyinformation or information contained in database 26 of such events,maintained by the directory assistance center. At this point, the callerwill be released from the call, and the operator becomes available tohandle further calls.

[0073] If the caller is seeking directory assistance, the operator willengage in live dialogue to establish the name and other pertinentinformation of the wanted party, and then initiate a database searchusing operator terminal 20 and associated database server 26. In theevent of an unsuccessful search, the operator will use alternativesources, such as the Electronic White Pages (EWP) or even printeddirectories. If requested, the operator can provide the addressinformation of the destination party in addition to, or in lieu of,initiating a telephonic connection to the destination party.

[0074] The operator can connect the caller to the wanted party's numberusing one of two possible methods of call transfer: Blind Transfer orHotline Transfer.

[0075] In either case, the call transfer is invoked by sending asequence of digits (that includes the wanted party's number) toswitching matrix host 28. The conventional method of doing this issimply dialing the digits on the operator's telephone handset (havingfirst depressed the “flash” key to obtain dial tone). This method isalways available. A much quicker and more accurate call completionmethod is generally preferred: the operator highlights the desireddatabase entry on the screen of the terminal 20, and then initiatesBlind or Hotline transfer to that number by entering a few keystrokes onthe terminal keyboard. In this case, database server 26 transmits thesame digit sequence as part of a message to switching matrix host 28,via data network 24.

[0076] More specifically, in the automated call completion method, theoperator locates the desired listing in the database, and presses the“enter” key at operator terminal 20 to select the listing. Whereupon,operator terminal 20 displays a main call completion menu along with aselected listing. One example of such a menu is as follows: Main CallCompletion Menu 1) Blind Transfer with Return Transfer 2) Blind Transferwith NO Return Transfer 3) Hotline Transfer with Return Transfer 4)Hotline Transfer with NO Return Transfer 5) Supervisor 6) Manual Dial 7)No connect

[0077] Options (1) and (2) of the main call completion menu initiate the“Blind Transfer” to the selected listing as described more fully below.Options (3) and (4) initiate the “Hotline Transfer” described more fullybelow. In the case of options (1) or (3), the return transfer operationwhich is described more fully below is enabled during the call. In thecase of options (2) or (4), the return transfer or transfer backoperation is disabled as also discussed more fully below. Option (5) isselected by the operator to summon the operator's supervisor forassistance handling the call. Option (6) overrides automated dialing ofthe selected listing, and allows the operator to manually dial a numberat operator terminal 20. Option (7) cancels call completion.

[0078] When the operator selects option (6), the operator terminal 20displays a call completion sub-menu such as follows: Manual Dial CallCompletion Sub-Menu Enter telephone number                 1) BlindTransfer with Return Transfer 2) Blind Transfer with NO Return Transfer3) Hotline Transfer with Return Transfer 4) Hotline Transfer with NOReturn Transfer 5) Supervisor 6) Change Number 7) No connect

[0079] Upon selection of any of the connection options (1)-(4) of eitherthe main call completion menu or manual dial call completion submenu,database server 26 sends a data packet to switching matrix host 28, viadata network 24. The data packet contains the appropriate station ID andthe digit sequence of the selected listing or manually entered telephonenumber in the case of option (6). A flow chart illustrating the processof sending a data packet to the switching matrix host is provided inFIG. 5.

[0080] “Blind Transfer” is the normal means by which an operatorestablishes a connection between the caller and the wanted party'snumber. As soon as switching matrix host 28 receives the Blind Transfercommand (whether from database server 26 or an operator's telephone set18), an attempt is made to establish a route out of switching matrixplatform 14 to the destination carrier's switching center, which may beeither the caller's carrier switching center 34 or may be a separatenetwork's carrier switching center.

[0081] In a SS7 network, this procedure occurs through transmission ofan Initial Address Message (IAM) by the directory assistance node, areply Address Complete Message (ACM) by the destination carrier's SS7network node, and an Answer Message (ANM) from the directory assistancenode if the call is successful. In this context, because a telephonicconnection to the directory assistance center has already beenestablished from the perspective of the caller's carrier switch, thedirectory assistance switch acts as an independent originating switch.For example, if the destination carrier's network node sends a ReleaseMessage (REL) to the directory assistance node because the line is busy,the directory assistance node does not transmit the REL down thesignaling line to the caller's carrier network node because thetelephonic connection to the directory assistance center is stillnecessary if the caller wishes to accomplish a return transfer.

[0082] During the pendency of this process, the operator is releasedfrom the call and made available to receive further calls. If VRU 30 isoperational, it is commanded to play a signoff message (pre-recorded bythe just-released operator). If the VRU is not available, the operatorspeaks the signoff message before initiating the transfer. The VRUstatus is known by whether the call was initiated by a VRU-playedgreeting, or by zip tone. Failed routing attempts cause reorder tones tobe returned to the operator's handset, or an error indication to bereturned to database server 26 (depending on how the switching matrixhost received the transfer command).

[0083] In one embodiment of the present invention utilizing SS7technology, the call set-up procedure determines whether the desiredparty's line is busy nearly instantaneously (by sending out an InitialAddress Message), even before the VRU plays a signoff message. If thedesired party's line is busy, the VRU plays a message informing thecustomer that the desired number is busy, and providing the customerwith a menu of options, including returning to an operator or arecitation of the desired phone number. While this message is beingplayed, the directory assistance node re-queries the destinationcarrier's network node by resending another IAM message. If thedirectory assistance system determines the destination number is nolonger busy, the present message ceases to play and the VRU insteadinforms the caller that the desired number is no longer busy, andcommences once again with the signoff message.

[0084] Like Blind Transfer, the “Hotline Transfer” method ofestablishing a connection between the caller and the wanted party'snumber can be initiated by the operator from either telephone handset 18or from data terminal keyboard 20. The difference is that the operatoris not automatically released from the call in a Hotline Transfer.Instead, he/she is conferenced into the call by switching matrix host 28using SS7 call processing and is able to monitor its progress. Usingeither the telephone handset or the data terminal keyboard, the operatormay withdraw from the call after verifying its establishment, or maycause the called circuit to be released through SS7 processing and thenre-engage in dialogue with the caller. A flow chart illustrating theprocess of a Hotline Transfer is provided in FIG. 6. Hotline Transfersare used when a caller requests that the operator “stay on the line.”

[0085] If, after initiation of a transfer (whether or not it succeeds),and at any time before the caller hangs up, the caller requires furtheroperator assistance, the caller can perform a return transfer back to anoperator (hereafter referred to as “return transfer” or “transferback”). This is done simply by pressing the “*” (star) key or anotherdesignated key on the caller's telephone once or twice (depending on thesystem, and as instructed by the operator in the signoff message).Generation and detection of the customer-issued return transfer commandcan occur through DTMF tones or through SS7 signaling messages. Theunderlying call transport system is a SS7 network.

[0086] In one embodiment of the present invention, the return transferfunction is implemented when an appropriate SS7 signaling message isdetected at the directory assistance node. One of the functions of SS7messaging in a SS7 network is to provide call control signaling. Callcontrol signaling includes, for example, a data message from the carrierSS7 network node indicating that one of the parties to the call haspushed a particular key, such as the “*” key or even a dedicated,specialized key (e.g. a “return to operator” key). An example of a SS7return transfer signaling message is described in further detail below.

[0087] Phone companies and wireless carriers can use equipment at theirswitching centers to detect DTMF tones from the voice channel andconvert them to out-of-bands signal to be sent down the signalingchannel. Wireless carriers, and in particular digital networks, may noteven need to convert customer key presses from analog DTMF tones todigital SS7 messages as the wireless stations may receive key presses indigital format to begin with. Phone companies and wireless carriers mayalso utilize phones that directly link to the out-of-band signalingnetwork, whereby the press of certain keys (such as a “return tooperator” key) will directly generate appropriate out-of-band signals.Voice recognition technology in a customer's phone or at a carrier'sswitch can also be used to detect a spoken customer command (e.g.“please return me to an operator”), in response to which an appropriateout-of-band signal would be generated correspondingly.

[0088] In another embodiment, the star or other designated key tone(s)is detected by a DTMF receiver at the directory assistance center(allocated in switching matrix platform 14 for the entire duration ofthe call), while the underlying call transport system utilizes a SS7network. Thus, call set-up, monitoring and tear-down occurs viaout-of-band signaling messages, while a DTMF receiver allocated to thevoice channel monitors for a return transfer command. A flow chartillustrating the process of allocating a DTMF receiver in the telephoneswitch to a customer call for the entire duration of the call isprovided in FIG. 7.

[0089] To avoid duplicative DTMF and SS7 return transfer commanddetection, in one embodiment the directory assistance center storesinformation for each carrier/phone company customer in database server26, indicating whether that customer provides SS7 messaging for returntransfers and other commands. If the carrier or phone company doesprovide out-of-band signaling for the “*” or other command key, thedirectory assistance center will not allocate a DTMF receiver for a callreceived from that company's switching center. Advantageously, detectionresources are thereby preserved and duplicative command detectionavoided.

[0090] Regardless of which form of return transfer command detection isused, once the DTMF receiver or directory assistance node detects theissuance of the return transfer command by the caller, a SS7 ReleaseMessage is sent from the directory assistance node to the destinationparty's carrier network node. In response, the destination party'scarrier network node issues a Release Complete Message, which, afterbeing received by the directory assistance node, results in the state ofthe corresponding voice connection 12 being set to idle in preparationfor the next call.

[0091] After the connection to the destination party is released,switching matrix host 28 causes the customer call itself to appear as afresh call to the ACD logic or other distribution scheme being utilized.This in turn results in the caller being connected to an availableoperator, whereupon switching matrix host 28 instructs the connected VRU30 to play the appropriate pre-recorded greeting message with returntransfer instructions. Note that if ACD is the operative distributionscheme, the operator to whom the call is connected may or may not be thesame operator that previously handled this call. In one embodiment ofthe present invention, the call is flagged as a priority call whenre-inserted into the queue, and hence is directed to an availableoperator sooner than other non-return transfer calls. In an alternativeembodiment, the caller is always connected to the same operator whopreviously handled the call, taking priority over other non-returntransfer queued calls for that operator.

[0092] The “return transfer” feature enables callers who have beentransferred by means of a Blind Transfer to recall an operator if thetransfer does not complete satisfactorily. It also enables a caller torequest a follow-on call at the completion of a successfully completedcall without incurring the delay or difficulty of re-dialing into thesystem.

[0093] It will be recognized that the desired number need not be voicedto the customer unless explicitly requested. Sometimes a customer usesthe return transfer feature to request that the number be voiced if, forexample, he or she finds a follow-up call is necessary later.

[0094] The return transfer technique enables the cost-effectiveprovision of many services not previously available. For example, adirectory assistance center may offer mapping/locator services whichprovide spoken directions to guide vehicle-based customers from theirpresent location to a desired destination. However, to obviate the needfor the customer to write the directions down while in the vehicle, theoperator should be available to issue instructions along the course ofthe vehicle's route. By using the return transfer feature, the customercan receive initial instructions, and thereafter summon furtherinstructions as needed along the route simply by pressing the star orother designated key. In such a system, the customer's connection to thedirectory assistance center is maintained during the course of the trip,but the operator can attend to other customers while the travelingcustomer doesn't need the operator's immediate attention. (Since areturn transfer may return the customer to a different operator,provision is made for transferring—with the customer—a pointer to theparticular database record (i.e. map or directions) being utilized bythat customer, and a pointer to a current location within that record.By this arrangement, a different operator who is summoned for assistanceusing the return transfer feature can pick up where the last operatorleft off.) While driving between operator instructions, the customer issimply kept in a “hold” state.

[0095] Sometimes the customer will be connected to a destinationtelephone number that makes its own use of “*” or other designated keytone. For example, some automated order entry systems require the callerto press the “*” key to signal the end of an entry, etc. Others requirethe caller to press the “*” key to access certain information.

[0096] To accommodate such possibilities, one embodiment of the presentinvention stores data in database 26 to indicate which destinationnumbers make their own use of the “*” key or other transfer backdesignated key or key series. If the customer is connected to such adestination telephone, the return transfer SS7 message or DTMF tonedetection is disabled. Alternatively, a destination telephone may sendthis information directly to the directory assistance center during callinitiation via an SS7 message. A flow chart illustrating the process ofdisabling the return transfer feature is provided in FIG. 8. If the userpresses the “*” key while connected to such a destination number, it isignored by directory assistance center 10. But, when the customerthereafter calls another destination telephone number that is not solisted in the database, the return transfer feature is once againavailable.

[0097] Sometimes database 26 may not contain complete informationidentifying destination numbers that make their own use of the “*” key.Moreover, some directory assistance systems may not track this data atall. In such circumstances, the directory assistance center 10 desirablyincludes provision to manually disable the return transfer SS7 messageor DTMF tone detection. This disabling can be done by operating a switchat the operator's console, by entering a command on the operator'skeyboard, or by activating an icon on the operator's terminal 20.

[0098] Such a manual disabling of the return transfer SS7 message orDTMF tone detection can occur, for example, when a caller isinadvertently transferred back to the operator by using the “*” key toaccess a service at the destination number. The caller can note theproblem to the operator, who can disable the feature and reconnect thecaller to the destination number. In other situations, the caller mayknow in advance that the destination number makes use of the “*” key(e.g. for electronic banking), and can request that the operator disablethe return transfer SS7 message or DTMF tone detection before theconnection is first made.

[0099] Another option is to allow enabling or de-enabling of the returntransfer feature to be particular to the customer, as opposed to thedestination telephone number. In this scenario, database server 26 wouldstore information personalized to each calling customer, identifyingwhether the customer prefers to have the return transfer feature on oroff. When an incoming call is received, switching matrix host 28 canidentify the calling customer through the associated SS7 call initiationmessages (such as the customer's Automatic Number Identification, orANI), do a look-up in database server 26 as to the return transferfeature preference of the customer, and then either enable or de-enablethe return transfer SS7 message or DTMF tone detection as appropriate.The preference for each customer for various features can be obtainedfrom the customer directly (either through a live operator or anautomated query), or through the customer's carrier provider. Thecarrier provider can collect this information from, for example, a queryon a customer's bill.

[0100] Another call feature available to the caller after completion ofa telephonic connection to the desired party, and at any time before thecaller or called party hangs up, is a conferencing feature. Thisfeature, like a return transfer, is initiated by the customer bypressing a specific key such as the “#” key or another designated key onthe caller's telephone once or twice (depending on the system, and asinstructed by the operator in the signoff message). Detection of theconferencing command, like a return transfer command, can occur throughan SS7 signaling message transmitted to the directory assistance node orthrough allocation of a DTMF receiver for the call in the switchingmatrix platform.

[0101] In either case, after the directory assistance center detects acommand for conferencing, the additional destination number must beascertained. In one embodiment, this occurs by switching matrix platform14 conferencing an operator into the existing call using SS7 processing.The operator will then prompt the customer for either the telephonenumber of the additional party if known, or if unknown, the operatorwill engage in dialogue to establish the name and other pertinentinformation of the wanted party and then initiate a database search.Once the additional destination number is determined, the operator caneither perform a Blind or Hotline transfer, just as with the initiationof the original call. The outgoing call is placed to a third networkswitch, which may or may not be the same network switching center as thesecond (the called party's switch) or the first (the caller party'sswitch), depending on which carrier network the various parties use.

[0102] As with the telephonic connection to the original destinationparty, the initialization of the conferencing telephonic connectionoccurs via SS7 call set-up procedures, with switching matrix platform 14operating as the originating switch. In a SS7 network, this procedureoccurs through transmission of an Initial Address Message (IAM) from thedirectory assistance network node, a reply Address Complete Message(ACM) from the destination carrier's network node, and an Answer Message(ANM) back from the directory assistance network node if the call issuccessful. The attempted conferencing telephonic connection is bridgedinto the existing telephonic connection between the caller and thecalled party such that the parties can hear the ringing tones or busysignal.

[0103] In the event the call transfer occurs via Blind Transfer, and theconnection cannot be established because of a ring-no-answer or busycondition, in one embodiment the switching matrix host will direct theVRU to announce that connection cannot be completed, and to present thecaller with a menu of choices, including attempting to reestablish theconnection, attempting to conference in a different party, returning toan operator or terminating the conference attempt. The directoryassistance center then responds appropriately to the customer'sselection. If the connection is successfully established, theconferencing connection is bridged into the existing telephonicconnection.

[0104] In an alternative embodiment, an operator is not utilized todetermine the telephone number of the additional desired party. Instead,the VRU prompts the caller to enter or speak the number for the party(this method only works if the calling customer actually knows thenumber for the additional party in advance). Thus, using SS7 messagedetection, DTMF tones or voice recognition capabilities, the switchingmatrix host ascertains the additional destination number from thecaller's input.

[0105] In another embodiment of the present invention, after thedirectory assistance center detects a command for conferencing, thecalling customer is offered a menu of choices for determining thetelephone number of the additional desired party, including speaking toan operator or using an automated number entry system through the VRU.

[0106] At any time after the conferencing connection has beensuccessfully established, the caller can again initiate a command forconferencing by pressing the “#” or other designated key. The procedureoutlined above is repeated again, and if successful, a fourth party canbe conferenced into the call. This process can be repeated up to thelimitations of the switching matrix platform for bridging callstogether.

[0107] Alternatively, the conferencing feature can be conducted via a“third-party calling” procedure. By this method, upon detection of thecommand for conferencing, the calling customer is disconnected from thetelephonic connection to the destination party, including voiceconnection 12, without actually releasing the call. Instead, the callingcustomer is treated like a new, independent outgoing telephonicconnection to be attempted. The customer hears a dial tone, as if thecustomer had just gone off-hook. After the customer places the calldirectly by dialing, SS7 call initiation procedures are used to attempta conferencing telephonic connection. Upon a successful connection, thecaller is able to “switch” (bridge) the conferencing connection over tothe original connection by pressing a predetermined key or by brieflyholding down the hang up switch. Alternatively, the switching matrixhost, upon detection of a successful call completion on the independentvoice line, can automatically bridge the two connections together.

[0108] Both the “return transfer” and “conferencing” features areinitiated when the customer issues a command to do so, which in oneembodiment would be through pressing the “*” or other designated key.One of skill in the art will appreciate that any numeric, alphanumericor other dedicated key can also function as a command key. Inalternative embodiments, the customer's actions can imply a command(e.g. if told that the call will be returned to an operator unless thecustomer presses “*”, and the caller does not press “*”), or voicerecognition technology in a customer's phone or at a carrier's switchcan be used to detect a spoken customer command (e.g. “please return meto an operator”).

[0109] In one embodiment, instead of having multiple keys each representdifferent optional commands, the directory assistance center stores apreferred feature or service associated with each customer in databaseserver 26. When a transfer by the operator is made to initiate thedesired telephonic connection, and database server 26 sends switchingmatrix host 28 the destination telephone number and station ID, it alsoincludes the customer's preferred service. If the database server doesnot have a preferred service for the customer in its data, it sends adefault service, such as a return transfer function. Examples ofpreferred services include conferencing, re-attempting to establish atelephonic connection (i.e. reinitiating the SS7 call initiationprocedure), creating a voice mail to be delivered at a later time, etc.

[0110] When the customer initiates a command for the preferred serviceby pressing a universal command key, such as the “*” key, and upon SS7message or DTMF tone detection of the same, the switching matrix hostexecutes the appropriate preferred function. In this manner, the callerobtains customization of the enhanced directory assistance features tohis or her personal preference. To initially establish a callingcustomer's preferred service, the operator can query a customer wholacks a specified preferred service, and manually input the answer intodatabase server 26. Alternatively, the selection of the preferredservice can occur automatically through a menu of options presented tothe customer by the VRU, or from the customer's phone company/carrier,which can obtain the information via account setup or survey and providethis information to the directory assistance center.

[0111] Thus far, customer-initiated return transfer, conferencing andpreferred service features have been described. It will be appreciated,however, that any feature can be linked to a customer initiated command.In one embodiment, if the customer presses a command key, such as the“*” key, which is then detected via SS7 signaling or a DTMF receiver,the VRU presents the caller with a menu of service options. Examples ofpotential service options might include returning to an operator,re-attempting to establish a connection to the destination telephonenumber, conferencing, reciting the destination telephone number, sendingan alphanumeric page of the destination telephone number, or resumingthe telephonic connection in progress. The user is then prompted toenter a selection, either by pressing the appropriate key (i.e. “press‘1’ to return to an operator, ‘2’ to re-attempt the call,”etc.) or byspeaking the selection (using the voice recognition capabilities of theVRU). Advantageously, automating the customer-initiated features cutsdown on the time that a live operator needs to speak with a customer.If, for example, a destination number is busy but the caller wishes toretry the connection, using an automated menu allows the caller toself-select the re-attempt instead of requiring an operator.

[0112] One advantage of using a SS7 network is that discrete, nearlyinstantaneous signaling messages are transmitted from the destinationparty's carrier network node to the directory assistance node indicatingthe status of the telephonic connection. Examples of SS7 call controlmessages include: call-could-not-be-completed, number-is-disconnected,busy signal, network communication problem, or caller or called partyhang-up.

[0113] In one embodiment of the present invention, the switching matrixhost can execute a predetermined service feature in response to SS7 callcontrol signaling, as detected at the directory assistance node. Forexample, the caller can automatically be returned to an operator everytime that a signaling event indicative of a problem, or a hang-up bycaller or called party, is encountered. In routing the call back to anoperator, the caller can be put into a ACD queue or given priority toreconnect to the original operator the customer was transacting with.When an appropriate operator receives the call at an operator station,the operator sees on operator terminal 20 the signaling eventencountered (sent by the switching matrix host) and can thus discuss thesituation with the caller and the available options. This approachensures that a wide range of communication events can be dealt with by auniversal automatic response (return to operator), as a human operatorcan provide the widest range of assistance in the highest number ofcontexts.

[0114] In an alternative embodiment, switching matrix host 28 directsVRU 30 to play a message corresponding to the signaling eventencountered, explaining to the caller the signaling event that hasoccurred (e.g. that the line is busy). The VRU then presents the callerwith an appropriate audio menu offering several directory assistanceoptions. The caller chooses one by pressing the specified key, forexample, the “1” key to have the VRU recite the dialed telephone number,the “2” key to transfer the called to a live operator, the “3” key torecord a message for later delivery to the destination party, the “4”key to re-attempt to initiate the call, or the “5” key to receive thedestination telephone number via the caller's alphanumeric page ortelephone. The caller chooses a selection by entering the appropriatekey, or alternatively by speaking a selection which the VRU's voicerecognition capabilities detect and identify.

[0115] The menu presented to the caller is tailored to the signalingevent encountered. Thus, the several illustrative options presentedabove are responsive to a busy signal from the destination telephonenumber. If the signaling event were a network condition affectingoutgoing calls, for example, the user would not be presented with theoption to attempt to reestablish the connection.

[0116] The automatic service response to a signaling event that has beendescribed is particularly advantageous to wireless and PCS phonecustomers. The automatic return to operator or automatic voice responsemenu ensures that a customer never has to hang up and redial thedirectory assistance center to obtain continued or additional directoryassistance services. The termination of the call occurs wholly at thecustomer's selection by either hanging up, or by choosing a voice menuselection for ending the call. The customer is left with the impressionthat the directory assistance center is dedicated to reaching the endresult desired by the customer.

[0117] SS7 Signaling Messages

[0118] As is well known in the art, an SS7 signaling message typicallycontains a variable numbers of octets (i.e. eight-bit bytes) ofinformation, with the front-end octets typically being reserved forstandardized service, routing and range and status data. Additionaloctets may contain a variety of communication and processing-orienteddata. For purposes of illustration, an example of an SS7 messageconveying a customer request for a return transfer will be describedherein.

[0119] In one example of an SS7 return transfer message, data for a setof “optional parameters” and a series of sets of “sub-optionalparameters” are set forth after the service, routing and range andstatus data. The optional parameters set includes a first octet settingforth the total number of octets in the optional parameters set (whichin the present example would be four), a second octet setting forth thedevice type from which the return transfer command originated, a thirdoctet setting forth the capabilities of the device and a fourth octetsetting forth the number of sub-optional parameters data sets. Thedevice type octet specifies whether the originating device is, forexample, a PDA (personal digital assistant), a PC, a phone, a wirelessphone, a web-enabled phone, etc. (also known as a devicecharacteristic).

[0120] The device capabilities octet specifies the possiblecommunication mediums of the device, such as voice, video, graphical, ortext. If the device capabilities octet indicates graphics or textcapabilities, the same octet would also indicate the language orrepresentation scheme of the text/graphics (also known as a devicecharacteristic), such as HTML (Hypertext Markup Language), ASCII(American Standard Code for Information Exchange), XML (ExtensibleMarkup Language) or WML (Wireless Markup Language). Additionally, thedevice capabilities octet specifies the protocols supported by thedevice, such as HTTP (Hypertext Transfer Protocol), WAP (WirelessApplication Protocol), UDP (User Datagram Protocol) or TCP (TransactionControl Protocol).

[0121] The final optional parameter octet sets forth the number ofsub-optional parameter sets. Each sub-optional parameter set has a firstoctet setting forth the total number of octets in that particularsub-optional parameter set (which in the present example would be four),a second octet indicating the sub-optional parameter type (e.g. action,data, or class of service), a third octet containing a data type for thesub-optional parameter set (e.g. command, digits, or text) and a fourthoctet containing appropriate data.

[0122] For an “action” sub-optional parameter type, the data typeindicated in the third octet would be “command,” and the actual data inthe fourth octet would indicate that the customer has pressed, forexample, the star or other specialized key which is recognized as acommand for a return transfer function.

[0123] For a “class of service” sub-optional parameter type, the datatype indicated in the third octet would be “digits” (and indicated asBCD, hexadecimal, binary, etc.) or “text”, and the actual data would setforth such status items as whether the customer was authorized toconnect to an operator, whether long distance is permitted, the languageof the customer, the priority level of the customer, etc. Thesecustomer-specific features are also known as customer serviceparameters.

[0124] For a “data” sub-optional parameter type, the data type indicatedin the third octet would be “digits” or “text,” and the actual datawould set forth phone numbers, network addresses, physical locations,PIM account indications, etc.

[0125] In one embodiment of the present invention, a SS7 return transfermessage includes two sub-optional parameter sets (and hence the lastparameter of the optional parameters set would be two). The firstsub-optional parameter set is an “action” sub-optional parameter typewith a “command” data type and data specifying a request for a returntransfer. The second sub-optional parameter set is a “class of service”sub-optional parameter type with a “digits” data type and dataspecifying whether the customer is allowed to make return transferrequests, whether the customer is a priority or preferred customer andthe language of the customer caller. After the last sub-optionalparameter set, a checksum value is appended to the SS7 message foraccuracy and error-checking.

[0126] As is true with all SS7 messaging, an acknowledgment message issent to the originator of a command for service. Thus, in one embodimentof the present invention, after the directory assistance center receivesan SS7 return transfer command message, it sends an acknowledgment SS7message which substantially mirrors in form the incoming SS7 returntransfer message. For the optional parameter device type, theacknowledgment message will indicate, for example, a positiveacknowledgment, an invalid device or an invalid device for theparticular customer. For the optional parameter device capabilities, theacknowledgment message will indicate, for example, a positiveacknowledgment, an invalid capability for the device specified,communication medium disallowed for user, service unavailabletemporarily, service unavailable in this area or service unavailablepermanently.

[0127] For acknowledgment of the sub-optional parameter sets, if thesub-optional parameter type is action, the acknowledgment message willindicate, for example, a positive acknowledgment, unable to completeaction, invalid action, invalid action for the user, invalid action forthe service type or invalid parameters supplied for the action. If thesub-optional parameter type is class of service, the acknowledgmentmessage will indicate, for example, a positive acknowledgment, unable toprovide class of service, invalid class of service for device type orinvalid parameters provided for class of service. If the sub-optionalparameter type is data, the acknowledgment message will indicate, forexample, a positive acknowledgment, invalid data for data typespecified, invalid data for device type or invalid data forcapabilities.

[0128] Billing Issues

[0129] Although these can be varied, there are three billing componentsof a typically wireless phone originated call to a directory assistanceservice according to the present invention:

[0130] 1) “Air time,” or the total time the caller uses the wirelesscarrier's wireless radio system to carry a call from his/her wirelesstelephone. This is the responsibility of the wireless carrier.

[0131] 2) The per-call charge levied for use of the directory assistanceservice. This charge is made by the directory assistance service to thewireless carrier on the basis of the number of calls received from thecarrier in a particular time period.

[0132] 3) Toll charge—the charge levied by a carrier for the duration ofan answered connection over a toll route originated by a directoryassistance operator. This charge is levied by the carrier used forcompletion of customer calls originated by the directory assistanceoperator. The wireless carrier is dependent on the directory assistanceservice to provide enough details of these calls to enable it toaccurately bill its subscribers accordingly, if desired. There are twoways of doing this:

[0133] A) The directory assistance service provides “tickets” of allcalls that were transferred and answered. The precise content and formatof the ticket is customer-defined, but includes at least the followinginformation: calling number, called number, date and time of connection(i.e. when answer indication was received), duration of call and trunkgroup identification numbers. The ticket files can be transferred onmagnetic tape or by means of electronic file transfer.

[0134] B) If the call to the destination party is being placed on thesame wireless network as that used by the calling customer, the wirelessnetwork can use its own switching equipment to generate the requiredtickets. The digits that are dialed by the directory assistanceservice's switching matrix platform to initiate the call transfer (viathe wireless carrier's network) can incorporate the calling party number(Automatic Number Identification, or ANI). The wireless carrier's ownswitching equipment then has all the information needed to generate therequired tickets. In a SS7 environment, the relevant information iscontained in the signaling data transmitted during the call-initiationprocess, and easily stored for use in tickets.

[0135] It is the wireless carrier's responsibility to rate the calls anddetermine what charge is to be levied.

[0136] Having described the principles of our invention with referenceto various embodiment and certain variations thereon, it should beapparent that these examples can be modified in arrangement and detailwithout departing from such principles. For example, while the inventionhas been illustrated with reference to a system in which a “returntransfer” customer is either routed back to the next available operatoror routed back to the original operator, in other embodiments, provisioncan be made for giving the customer a choice: pressing one key for thefirst available operator, and another key to be inserted in the originaloperator's queue.

[0137] In view of the many possible embodiments to which the principlesof our invention may be put, it should be recognized that the detailedembodiments are illustrative only and should not be taken as limitingthe scope of our invention. Rather, we claim as our invention all suchembodiments as may come within the scope and spirit of the followingclaims and equivalents thereto.

What is claimed is:
 1. An enhanced method of providing telephonedirectory assistance from a directory assistance center having adirectory assistance node and a directory assistance switch, the methodcomprising the steps: (a) receiving a customer call through a firstnetwork switch from a customer telephonic device in an externaltelephone network; (b) receiving signaling data associated with thecustomer call through a network node; (c) connecting the customer callthrough the first network switch to the directory assistance switch overa first voice connection between the directory assistance switch and thefirst network switch; (d) connecting the signaling data associated withthe customer call to the directory assistance node over a dataconnection between the directory assistance node and the network node;(e) connecting the customer call to a directory assistance operator; (f)determining a destination telephonic device number of a desired partywanted by the customer in a computer database; (g) initiating atelephonic connection between the customer telephonic device and thedestination telephonic device over a second voice connection between thedirectory assistance switch and a second network switch, the telephonicconnection being responsive to one of a plurality of connection options,at least one of the connection options including the following steps(h)-(i); (h) detecting at the directory assistance node one or moreinstances of a command issued by the customer; and (i) performing apredetermined function upon detection of one or more instances of thecommand.
 2. The method of claim 1, wherein the predetermined function instep (i) comprises reconnecting the customer to an operator.
 3. Themethod of claim 1, wherein the predetermined function in step (i)comprises re-attempting to establish a connection between the customertelephonic device and the destination telephonic device.
 4. The methodof claim 1, wherein the predetermined function in step (i) comprisesproviding the destination telephonic device number to the customer. 5.The method of claim 1, wherein the predetermined function in step (i)comprises recording a message for later delivery to the destinationtelephonic device.
 6. The method of claim 1, wherein the predeterminedfunction in step (i) comprises prompting the customer for analphanumeric page to be sent to the destination telephonic device. 7.The method of claim 1, wherein the predetermined function in step (i)comprises presenting the customer with a plurality of service options.8. The method of claim 7, wherein one of the plurality of serviceoptions includes reconnecting the customer to an operator.
 9. The methodof claim 7, wherein the plurality of service options include at leastone of the following options: resuming the telephonic connection inprogress, re-attempting to establish a connection between the customertelephonic device and the destination telephonic device, providing thedestination telephonic device number to the customer, recording amessage for later delivery to the destination telephonic device, orprompting the customer for an alphanumeric page to be sent to thedestination telephonic device.
 10. The method of claim 1, wherein thefirst network switch and the second network switch comprise a singlenetwork switch.
 11. The method of claim 1, wherein the signaling dataassociated with the customer call is received from an externalout-of-band signaling network.
 12. The method of claim 1, furthercomprising the steps of: maintaining the first voice connection from thecustomer telephonic device through the first network switch to thedirectory assistance switch for the duration of the customer call; andmaintaining the data connection associated with the customer callthrough the network node to the directory assistance node for theduration of the customer call.
 13. The method of claim 1, wherein step(g) further comprises: transmitting call initiation signaling data overthe data connection to a second network node to initiate a telephonicconnection between the customer telephonic device and the destinationtelephonic device; and upon receipt of confirmatory call initiationsignaling data, establishing the telephonic connection between thecustomer telephonic device and the destination telephonic device over asecond voice connection between the directory assistance switch and asecond network switch.
 14. The method of claim 1, wherein the telephonicconnection between the customer telephonic device and the destinationtelephonic device is comprised of a voice channel and a signalingchannel, and wherein the voice channel is initiated over a second voiceconnection between the directory assistance switch and a second networkswitch, and the signaling channel is initiated over a second dataconnection between the directory assistance node and a second networknode.
 15. The method of claim 14, wherein the first network node and thesecond network node comprise a single network node.
 16. The method ofclaim 14, wherein the first network switch and the second network switchcomprise a single network switch.
 17. The method of claim 1 in which atleast one of the plurality of connection options includes the followingsteps (j)-(l): (j) allocating one or more detectors in the directoryassistance switch to monitor the customer call for a command issued bythe customer; (k) detecting at the directory assistance switch one ormore instances of the command; and (l) performing a predeterminedfunction upon detection of one or more instances of the command.
 18. Themethod of claim 17, wherein the predetermined function in step (l)comprises reconnecting the customer to an operator.
 19. The method ofclaim 17, wherein the predetermined function in step (l) comprisesre-attempting to establish a connection between the customer telephonicdevice and the destination telephonic device.
 20. The method of claim17, wherein the predetermined function in step (l) comprises providingthe destination telephonic device number to the customer.
 21. The methodof claim 17, wherein the predetermined function in step (l) comprisesrecording a message for later delivery to the destination telephonicdevice.
 22. The method of claim 17, wherein the predetermined functionin step (l) comprises prompting the customer for an alphanumeric page tobe sent to the destination telephonic device.
 23. The method of claim17, wherein the predetermined function in step (l) comprises presentingthe customer with a plurality of service options.
 24. The method ofclaim 18, wherein one of the plurality of service options includesreconnecting to an operator.
 25. The method of claim 23, wherein theplurality of service options include at least one of the followingoptions: resuming the telephonic connection in progress, conferencing inan additional desired party to the telephonic connection, reattemptingto establish a connection between the customer telephonic device and thedestination telephonic device, providing the destination telephonicdevice number to the customer, recording a message for later delivery tothe destination telephonic device, or prompting the customer for analphanumeric page to be sent to the destination telephonic device. 26.The method of claim 1, wherein step (g) comprises sending a digitsequence of the destination telephonic device number contained in thecomputer database to a switching matrix host to initiate the telephonicconnection.
 27. The method of claim 1, wherein step (g) furthercomprises initiating the telephonic connection without a voicedrecitation of the destination telephonic device number.
 28. The methodof claim 1, wherein step (g) further comprises providing the destinationtelephonic device number to the customer by a voice recording unit. 29.The method of claim 1 in which at least one of the connection optionsincludes the step of maintaining the directory assistance operator as aconferenced party to the initiated telephonic connection to monitorwhether the connection is completed satisfactorily.
 30. The method ofclaim 1, wherein the customer telephonic device and destinationtelephonic device are telephones.
 31. The method of claim 1, wherein thecustomer telephonic device is a wireless telephone.
 32. The method ofclaim 1, wherein the command issued by the customer results from animplied action by the customer.
 33. An enhanced method of providingtelephone directory assistance from a directory assistance center havinga directory assistance node and a directory assistance switch, themethod comprising the steps: (a) receiving a customer call from a firstnetwork switch from a customer telephonic device in an externaltelephone network; (b) receiving signaling data associated with thecustomer call from a network node; (c) connecting the customer callthrough the first network switch to the directory assistance switch overa first voice link between the directory assistance switch and the firstnetwork switch; (d) connecting the signaling data associated with thecustomer call to the directory assistance node over a data link betweenthe directory assistance node and the network node; (e) connecting thecustomer call to a directory assistance operator; (f) determining adestination telephonic device number associated with a desired partywanted by the customer in a computer database; (g) initiating atelephonic connection between the customer telephonic device and thedestination telephonic device over a second voice connection between thedirectory assistance switch and a second network switch, said telephonicconnection being responsive to one of a plurality of connection options,at least one of the connection options including the following steps(h)-(j); (h) detecting at the directory assistance node one or moreinstances of a command for conferencing issued by the customer; (i)determining an additional destination telephonic device number of anadditional desired party wanted by the customer in a computer database;and (j) initiating a conferencing telephonic connection between theadditional destination telephonic device and the connection between thecustomer telephonic device and the destination telephonic device, over athird voice connection between the directory assistance switch and athird network switch.
 34. The method of claim 33, wherein the signalingdata associated with the customer call is received from an externalout-of-band signaling network.
 35. The method of claim 33, wherein step(i) further comprises reconnecting the customer to an operator todetermine the additional destination telephonic device number of theadditional desired party wanted by the customer from a computerdatabase.
 36. The method of claim 33, wherein step (i) further comprisesprompting the customer by voice recording unit to enter or speak theadditional destination telephonic device number of the additionaldesired party.
 37. The method of claim 33, wherein step (i) furthercomprises providing the customer with a plurality of options fordetermining and providing the additional destination telephonic devicenumber, wherein one of the options includes reconnecting to an operator.38. The method of claim 33 in which at least one of the connectionoptions includes the following steps (k)-(n): (k) allocating one or moredetectors in the directory assistance switch to monitor the customercall for a command for conferencing issued by the customer; (l)detecting at the directory assistance switch one or more instances ofthe command; (m) determining an additional destination telephonic devicenumber of an additional desired party wanted by the customer in acomputer database; and (n) initiating a conferencing telephonicconnection between the additional destination telephonic device and theconnection between the customer telephonic device and the destinationtelephonic device, over a third voice connection between the directoryassistance switch and a third network switch.
 39. The method of claim33, wherein the conferencing telephonic connection is responsive to oneof a plurality of conferencing connection options, and wherein at leastone of the conferencing connection options includes the step ofmaintaining the directory assistance operator as a conferenced party tothe initiated conferencing telephonic connection to monitor whether theconnection is completed satisfactorily.
 40. The method of claim 33,further comprising, upon an unsuccessful initiation of the conferencingtelephonic connection, providing the customer with a plurality ofservice options, wherein at least one of the plurality of serviceoptions includes returning to an operator.
 41. The method of claim 33,wherein step (i) occurs blindly with respect to the destinationtelephonic device.
 42. The method of claim 33, further comprising thesteps of: maintaining the first voice link from the customer telephonicdevice through the first network switch to the directory assistanceswitch for the duration of the customer call; and maintaining the datalink associated with the customer call through the network node to thedirectory assistance node for the duration of the customer call.
 43. Themethod of claim 33, wherein step (g) further comprises: transmittingcall initiation signaling data over the data connection to a secondnetwork node to initiate a telephonic connection between the customertelephonic device and the destination telephonic device; and uponreceipt of confirmatory call initiation signaling data, establishing thetelephonic connection between the customer telephonic device and thedestination telephonic device over a second voice connection between thedirectory assistance switch and a second network switch.
 44. The methodof claim 43, wherein the first network node and the second network nodecomprise a single network node.
 45. The method of claim 33, wherein step(g) comprises sending a digit sequence of the destination telephonicdevice number contained in the computer database to a switching matrixhost to initiate the telephonic connection.
 46. The method of claim 33,wherein the first network switch and the second network switch comprisea single network switch.
 47. The method of claim 33, wherein the firstnetwork switch, second network switch, and third network switch comprisea single network switch.
 48. The method of claim 33, wherein thecustomer telephonic device, destination telephonic device, andadditional destination telephonic device are telephones.
 49. The methodof claim 33, wherein the customer telephonic device is a wirelesstelephone.
 50. The method of claim 33, wherein step (g) furthercomprises initiating the telephonic connection without a voicedrecitation of the destination telephonic device number.
 51. The methodof claim 33 which includes repeating steps (h) through (j) for adifferent additional desired party.
 52. The method of claim 33 whereinthe command for conferencing issued by the customer results from animplied action by the customer.
 53. An enhanced method of providingtelephone directory assistance from a directory assistance center havinga directory assistance node and a directory assistance, the methodcomprising the steps: (a) receiving a customer call through a firstnetwork switch from a customer telephonic device in an externaltelephone network; (b) connecting the customer call through the firstnetwork switch to the directory assistance switch over a first voicelink between the directory assistance switch and the first networkswitch; (c) connecting the customer call to a directory assistanceoperator; (d) determining a destination telephonic device number of adesired party wanted by the customer in a computer database; (e)initiating a telephonic connection between the customer telephonicdevice and the destination telephonic device over a second voice linkbetween the directory assistance switch and a second network switch; (f)initiating a signaling data connection associated with the telephonicconnection over a data link between the directory assistance node and anetwork node; (h) upon detection at the directory assistance node of oneor more instances of a predetermined signaling event associated with thetelephonic connection between the customer telephone and the destinationtelephone, taking a predetermined action.
 54. The method of claim 53,wherein the network node is in an external out-of-band signalingnetwork.
 55. The method of claim 53, wherein the predetermined signalingevent in step (h) includes at least one of the following: call could notbe completed, ring-no-answer, called party termination of call,number-is-disconnected, busy signal, and network communication problem.56. The method of claim 53, wherein the predetermined action in step (h)comprises reconnecting the customer to an operator.
 57. The method ofclaim 53, wherein the predetermined action in step (h) comprisespresenting the customer with a plurality of service options.
 58. Themethod of claim 57, wherein the plurality of service options arespecific to the predetermined signaling event.
 59. The method of claim57, wherein at least one of the plurality of service options includesreconnecting to an operator.
 60. The method of claim 57, wherein theplurality of service options are announced by a voice response unit. 61.The method of claim 53, wherein the predetermined signaling event is abusy signal and wherein the predetermined action comprises informing thecustomer that destination telephone number is busy.
 62. The method ofclaim 53, further comprising the steps of: (i) detecting a subsequentsignaling event indicating that the destination telephone number is nolonger busy; (j) ceasing informing the customer that the destinationtelephone number is busy; and (k) reinitiating a telephonic connectionbetween the customer telephone and the destination telephone over thesecond voice link; and (l) reinitiating a signaling data connectionassociated with the telephonic connection over the data link.
 63. Themethod of claim 53, wherein the customer telephonic device anddestination telephonic device are telephones.
 64. The method of claim53, wherein the customer telephonic device is a wireless telephone. 65.An enhanced method of providing telephone directory assistance from adirectory assistance center having a directory assistance node and adirectory assistance switch, the method comprising the steps: (a)maintaining an attribute database of preferred services associated withindividual customers of the directory assistance center; (b) receiving acustomer call through a first network switch from a customer telephonicdevice in an external telephone network; (c) receiving signaling dataassociated with the customer call through a network node; (d) connectingthe customer call through the first network switch to the directoryassistance switch over a first voice connection between the directoryassistance switch and the first network switch; (e) connecting thesignaling data associated with the customer call to the directoryassistance node over a data connection between the directory assistancenode and the network node; (f) connecting the customer call to adirectory assistance operator; (g) determining a destination telephonicdevice number of a desired party wanted by the customer in a computerdatabase; (h) determining the preferred service associated with thecustomer from the attribute database; (i) initiating a telephonicconnection between the customer telephonic device and the destinationtelephonic device over a second voice connection between the directoryassistance switch and a second network switch, the telephonic connectionbeing responsive to one of a plurality of connection options, at leastone of the connection options including the following steps (j)-(k); (j)detecting at the directory assistance node one or more instances of acommand issued by the customer for the preferred service associated withthe customer; and (k) performing the preferred service upon detection ofone or more instances of the command.
 66. The method of claim 65,wherein the signaling data associated with the customer call is receivedfrom an external out-of-band signaling network.
 67. The method of claim65, wherein the preferred service comprises returning to an operator.68. The method of claim 65, wherein step (h) further comprisesdetermining a default preferred service if the attribute database doesnot contain a preferred service associated with the customer.
 69. Themethod of claim 65, wherein the customer telephonic device anddestination telephonic device are telephones.
 70. The method of claim65, wherein the customer telephonic device is a wireless telephone. 71.A method of generating an out-of-band signaling message affiliated witha customer command for enhanced directory assistance service issued froma customer telephonic device, the method comprising the steps of:detecting the customer command for enhanced directory assistance serviceissued from the customer telephonic device; generating a first datafield containing routing information for the out-of-band signalingmessage; generating a second data field identifying the enhanceddirectory service sought by the customer; and generating a third datafield identifying a protocol of the customer device.
 72. The method ofclaim 71, further comprising the step of generating a fourth data fieldidentifying customer service parameters associated with the customer.73. The method of claim 71, further comprising the step of generating afourth data field identifying a characteristic of the customertelephonic device.
 74. A method of processing an out-of-band signalingmessage affiliated with a customer command for enhanced directoryassistance service issued from a customer telephonic device, the methodcomprising the steps of: receiving the out-of-band signaling messageaffiliated with the customer command for enhanced directory assistanceservice issued from the customer telephonic device; processing a firstdata field of the out-of-band signaling message to obtain the enhanceddirectory service sought by the customer; and processing a second datafield of the out-of-band signaling message to obtain a protocol of thecustomer device.
 75. The method of claim 74, further comprising the stepof processing a fourth data field of the out-of-band signaling messageto obtain customer service parameters associated with the customer. 76.The method of claim 74, further comprising the step of processing afourth data field of the out-of-band signaling message to obtain acharacteristic of the customer telephonic device.